1. Field of the Invention
The present invention relates to a compound semiconductor substrate and a method of manufacturing the same.
2. Description of the Related Art
GaAs is known well as a type of a compound semiconductor. When the GaAs is made to have a resistivity of 10.sup.6 .OMEGA..multidot.cm or more, it has semi-insulating characteristics. When active elements are formed in a semi-insulating GaAs substrate, they are not advantageously required to be electrically isolated from each other using a field insulating film. In order to obtain this advantage, a semi-insulating GaAs single-crystal is conventionally made using a single-crystal manufacturing technique such as an LEC method, and the single-crystal is sliced to manufacture semi-insulating GaAs substrates.
Since the semi-insulating GaAs single-crystal is constituted by bonding two types of atoms, a shearing stress acting inside the GaAs single-crystal is stronger than that of a silicon single-crystal, and a dislocation density in the GaAs single-crystal is disadvantageously increased.